Ring fixator

Abstract

An external fixator apparatus ( 1 ) of the ring type for stabilizing bone fractures, including at least one pair of rings ( 6, 7 ), of which one ( 6 ) is proximal and the other ( 7 ) is distal, and at least one tie rod ( 8, 9, 10 ) interconnecting the rings ( 6, 7 ) to each other. The rod ( 8, 9, 10 ) is split into two rod sections ( 11, 12 ) connected together by a joint ( 21 ) and the joint ( 21 ) includes a pivot mount ( 22 ) having a predetermined axis (x—x) for the angular displacement of the rod sections ( 11, 12 ), and a sliding mount ( 23 ) according to a pre-determined sliding direction (y—y) for offsetting the rod sections ( 11, 12 ).

1. An external ring fixator apparatus for stabilizing bone fractures, comprising:
 at least one pair of rings, of which one is proximal and another is distal; and 
 at least one tie rod interconnecting the rings to each other, 
 wherein said at least one rod is split into two rod sections connected together by a joint, 
 wherein said joint comprises a pivot mount having a predetermined axis for the angular displacement of the rod sections and comprises a sleeve, 
 wherein the axis of the pivot mount lies perpendicularly to said rod sections, 
 wherein an offset between the rod sections is obtained by means of a slide mount having a predetermined sliding direction for offsetting the rod sections, and comprising a slider slidably mounted on a slide way extending along the pivot mount axis, the sliding direction of the slide mount being coincident with the pivot mount axis, and 
 wherein one end of one rod section is fixed to the slide way, and one end of the other rod section is fixed to the sleeve that is rotatably mounted on the slide way. 
 
     
     
       2. An external ring fixator according to  claim 1 , wherein the sleeve is rotatably mounted on a bush, itself slidably mounted on said slide way. 
     
     
       3. An external ring fixator apparatus for stabilizing bone fractures, comprising:
 at least one pair of rings, of which one is proximal and an other is distal; and 
 at least one tie rod interconnecting the rings to each other, 
 wherein said at least one rod is split into two rod sections connected together by a joint, 
 wherein said joint comprises a pivot mount having a predetermined axis for the angular displacement of the rod sections and comprises a slide mount according to a predetermined sliding direction for offsetting the rod sections, 
 wherein said pivot mount comprises locking means for locking the rod sections in a predetermined angular position, and 
 wherein the locking means of the pivot mount comprise a slit formed in the sleeve and a clamp screw extending across the slit. 
 
     
     
       4. An external ring fixator apparatus according to  claim 1 , wherein the slide mount includes an offset adjuster means. 
     
     
       5. An external ring fixator apparatus according to  claim 4 , wherein said adjuster means comprises an actuating screw and a threadway. 
     
     
       6. An external ring fixator apparatus according to  claim 1 , wherein the pivot mount is made of a material transparent to X-radiation. 
     
     
       7. An external ring fixator apparatus according to  claim 1 , wherein the slide mount is made of a material transparent to X-radiation.